第3085期:Melting glaciers threaten a sharp rise in water levels

Researchers at this camp overlooking Greenland's Helheim Glacier have some bad news.俯瞰格陵兰赫尔海姆冰川的营地研究人员带来了一些坏消息。This glacier has retreated more than 10 kilometers or so in the last decade or so, from that position far off and to my left to where you see it today.这条冰川在过去十多年间已退缩了10公里左右，从我左侧远处的位置退到了如今你们所见的地方。It was here in 2018 that researchers captured this footage of large chunks of ice breaking away in a process called calving.2018年，研究人员正是在这里拍摄到了大块冰体断裂脱落的画面，这一过程被称为裂冰作用。Scientists like New York University's David Holland measured and observed climate change. This summer Holland saw record-shattering heat and ice melt.纽约大学的戴维·霍兰德等科学家对气候变化进行了测量和观察。今年夏天霍兰德目睹了破纪录的高温和冰层融化现象。Large glaciers are retreating. We can detect this with satellite, with effectively cameras in space.大型冰川正在消退，我们可以通过卫星，也就是太空中的高效摄像头，观测到这一现象。And we're seeing a very large signal of melt coming from this one particular glacier out in West Antarctica called Thwaites.我们正观测到来自南极洲西部斯维斯冰川发出的非常强烈的融化信号。NASA and the European Space Agency or ESA released the study in December美国国家航空航天局（NASA）和欧洲航天局（ESA）于12月发布了这项研究，showing the Greenland icesheetrapidly melting, having lost nearly four trillion metric tons between 1992 and 2018.研究显示格陵兰冰盖正在迅速融化，在1992年至2018年期间已损失了近4万亿公吨。Holland says a similar fate appears underway in Antarctica.霍兰德说南极洲也出现了类似的情况。That glacier is holding back several other glaciers of the West Antarctic IceSheet.那座冰川阻挡着南极西部冰盖的其他几座冰川。So all told, it is conceivable and not that it will happen but it could happen, that up to 3 meters of global sea level could be unleashed unto us.综上所述，可以想象——虽然并非必然发生但确实存在可能性——全球海平面上升幅度可能高达3米。Cities like Alexandria, Egypt take countermeasures to slow crashing waves because of rising sea levels near ice shelves affect sea levels everywhere.由于冰架附近海平面上升会影响全球海平面，埃及亚历山大等城市采取应对措施以减缓海浪冲击。Warmer waters around retreating glaciers like the one in Antarctica expedite the process.南极洲等地冰川消退，周围水域温度上升，进而加速了这一过程。This glacier is perhaps unstable. It is certainly retreating now at a rapid rate.这座冰川或许不稳定。它现在确实在快速消退。It has raised its stuff to the point of now using physics, mathematics and observation.它已将研究提升至运用物理学、数学和观测的层面。It's actually credible, plausible that this thing could cause a major change in sea level.实际上可信的是，这可能导致海平面发生重大变化。A study published April in the journal Nature showed glaciers worldwide annually lose 369 billion metric tons of snow and ice.《自然》杂志四月发表的一项研究显示，全球冰川每年流失3690亿吨冰雪。The Greenland icesheetalone holds enough water to raise sea level by nearly seven and a half meters. 仅格陵兰冰盖所含的水量就足以使海平面上升近7.5米。